Heater for high temperature reactions and conversions



Nov. 25, 1947. v 1:). G. BRANDT 2,431,632

HEATER FOR HIGH TEMPERATURE REACTIONS AND CONVERSIONS Filed May 27, 1943 la y 4 INVENTOR MW 6. BRAMWT arrow; J

Patented Nov; 25, 1947 HEATER FOR HIGH TEMPERATURE REACTIONS AND CONVERSIONS David G. Brandt, Westfleld, N. 1., assignor to Cities Service Oil Company, New York, N. Y., a corporation of Pennsylvania Application May 27, 1943, Serial No. 488,703

1 Claim. (01. 23-284) This invention relates to improvements in heaters particularly adapted for effecting high temperature and high pressure reactions.

. Steel apparatus is commonly used and iseffective for conducting high pressure chemical or thermal conversions where the temperatures arenot high enough to materially efiect the strength of the steel. The development of special alloy steels has permitted the use of gradually higher temperatures, but very thick walled tubes and thick walled chambers have been used in order to ofiset the dangers due to heating such apparatus.

It is generally recognized, however, that steel and steel-alloys are quite unsuited for gas-making operations and other conversions where the temperatures exceed 1200' or 1300 F. This is especially true where any appreciable pressure is to be employed. In gas-making and other high temperature arts, the heating apparatus is almost invariably constructed of or faced with refractory brick or other refractory shapes which can withstand temperatures of 1800 F. and higher. Apparatus of thistype, however, have a. limited utility in the carrying out of chemical reactions and conversions, and are usually unsuited for high pressure work.

The primary object of the present invention is therefore to provide an apparatus in which high temperatures and high pressures may be used in effecting reactions and conversions.

A further object of the invention is to provide an apparatus in which temperatures may b used which are beyond those which can be employed in steel apparatus.

Another object of the invention is to provide an apparatus for heating fluids at temperatures and pressures which are impossible to use in metal apparatus. a

In general, the present invention comprises a heater for carrying out high temperature reactions and conversion which includes an outer sheet metal shell which is not subjected to the high 2 be apparent to those skilled in the art from the following more detailed description taken in connection with the accompanying drawings which forma part of this application.

In the drawings:

Fig. 1 is a side elevational view, partly in broken section, of a heating apparatus of the one-through tubular type, constructed in accordance with the features of the present invention.

Fig. 2 is a side elevational view in vertical section of an apparatus of the parallel tube-type, constructed in accordance with the features of the present invention.

Fig. 3 is a broken vertical sectional view showing one method of mounting porous refractory tubes inatube sheet.

Fig. 4 is a broken front view of a tube sheet mounting showing details for mounting groups of porous refractory tubes.

- The apparatus shown in Fig. 1 may comprise all or only a portion of a once-through tubular heater, constructed in accordance with the present invention, and to which is supplied the materials to be converted or reacted. This heater comprises an outer sheet steel casing ill, a relatively thick annular refractory layer of insulation l2 on the inside of the casing l0, and a spaced porous refractory tube or tubes Hi, substantially spaced from the inside wall of the insulation l2 so as to provide an annular space or a series of annular spaces to be supplied with relatively cool gaseous materials such as air, steam, mixtures of air and steam, or other suitable gases. The porous refractory tube It is preferably made up of a series of connected hollow tile members as shown, having annular bell-like sockets or expansion joint projections is which rest in the insulation l2 and serve to provide and establish the spacing between the layer of insulation I 2 and the main body of the tile members comprising the porous refractory tube M,

The converter shown in Fig. 1 includes two straight lengths of casing I0 fitted with inside insulation and porous tile, connected by a. return ioend of similar construction, as shown. Any number of straight lengths of easing similar to the ones shown may be used for making up the converter, or.a long straight converter may be made by connecting any desired number of the straight sections. Furthermore, any suitable means may be employed for supplying the materials. to be reacted or converted to the porous refractory tube, and any suitable apparatus may be employed 3 for handling the products of reaction discharged from the converter.

Air and other gases are supplied to the converter through a supply main l8 which is provided with valved connecting lines 20 which terminate in the spaces between the layer of insulation and the porous tile sections comprising the porous tube l4. In certain operations the air supplied through the main l8 may be highly superheated(900 to 1100 F.) and mixed with any desired proportion of superheated steam or other gases, depending upon the process. to be carried out in the converter. In any case, gas supplied through the main l8 into the spaces outside the porous tubular converter is relatively cool compared to the temperatures used inside the tube l4, so that a relatively thin casing I will be strong enough to withstand very high pressures because the high temperatures are restricted to porous refractory tube I4; The diffusion of gas through the porous refractory keeps the temperature of the lining l2 down. The gas supplied through the main I8 is of course kept at a pressure equal to or slightly above that of the materials reacted in the tube l4 so that the gas is constantly diffused through the porous refractory and is used to dilute the materials beingreacted, or to take part in the reactions being carried on inside the tube H. The tubular converter shown in Fig. 1 may have an inside diameter of from five inches to eight inches and may vary in length from twenty feet to 300 feet or more, depending upon the use to which the converter is applied.

Another form of converter constructed in accordance with the features of the present invention is shown in Fig. 2 in which a number of porous refractory tubes 22 are mounted for parallel flow in a casing 24 to provide a structure similar to that of a surface condenser. The casing 24 may be of relatively thin sheet steel, but sufficiently strong to withstand comparatively high pressures at moderate temperatures. This casing is provided with a flanged inlet 26 for steam, air or other gases, and this inlet as well as the entire casing 24 is lined with a thick layer of insulating material '28. The porous refractory tubes 22 are mounted in tube sheets 30 and 3| rial 44. The tube sheet 31 is protected in the head 38 from the high temperature products discharged from the tubes 22 by means of insulating material 46.

One method of mounting the porous refractory tubes 22 in the tube sheets is illustratedin Fig. 3

in which a bushing member 48, provided with,a

central opening equal to the inside diameter of tube 22, is fitted over the end of the tube, which may project slightly through the tube sheet 30, and is set in a packing slot containing a suitable packing material 58.' The tubes 22 need not be mounted in, tube sheets in a very rigid manner since minor leakage from around the tubes. into the heads is of little importance. member 48, however. together with the packing 50 which is preferably'somerefractory-type material, will provide a sufllcient seal, and at the 4 same time permit expansion and contraction of the tubes 22. g

A modified arrangement for sealing the ends of the tubes 22 with respect to the tube sheets, is shown in Fig. 4 in which bushing members 52 of triangular shape are made large enough to provide bushings for three tubes. The under side of the members 62 will be constructed similar to the bushing 48 with respect to the three tubes. If desired the members 52 may be provided with studs or other suitable means for securing them to the tube sheet 30 or 3|, as the case may be. The porous refractory tubes l4 and 22 are preferably made of some inert non-metallic refractory material which will withstand very high temperatures without fusion or slagging, and at the same time provide a material through which gases may be diffused.

The heating apparatus of the present invention may be employed to carry out various types of facture of water-gas in later stages of the operation by separately introducing superheated steam through some of the lines 20 or through other inlet lines similar to the lines 20. Similar operations may be carried out in the apparatus shown in Fig. 2.

Another example of the use of the heating apparatus of the present invention is in the partial oxidation of hydrocarbons in which hydrocarbon gases or vapors are introduced into the inlet of the porous refractory tube l4, and partially oxidized by the diifusion of oxygen, air or a mixture of one of these gases with steam or other suitable non-combustible gas. through the line 28. The oxygen-containing gas is preferably introduced along substantially the entire stream in the tube 14 to insure the partial oxidation of a substantial proportion of the inlet stream. This process may be carried out in the apparatus of 1 Fig. 2, although there is no means provided for I of the reaction. However, two or more units of The bushing the apparatus shown in Fig. 2 may be used in series.

Exothermic reactions may be carried on in the apparatus and inert gas may be diffused through the porous refractory to control the temperature and confine the high temperatures to the inner apparatus of Fig.1, and solid, catalysts may be revivifled. Carbon contained in such catalysts may be completely burned out, whereas at present, oil conversion catalysts are only partly revivified and only a part or the carbon is burned out. y

Various other processes. may becarried out in the apparatus of the present invention, as will occur to those skilled in the art. The apparatus will have a considerable advantage in the carrying out of processes which normally involved the production or deposition of carbon or coke. In this apparatus, carbon or coke cannot be deposited on the walls of the reaction tubes because air or other gases are continuously diffused therethrough and therefore keep the walls clean and free of any deposits. It will furthermore be apparaent that other types of reactions which normally precipitate solids or other materials may be carried out in the apparatus effectively without causing any deposits in the tubes and at the same time provide intensive heating and agitation. The apparatus is particularly adapted for effecting high temperature and high pressure reactions which must be carried out at temperatures above those at which metal apparatus can be safely employed.

From the foregoing description it will be apparent that various modifications may be made .in the structure and arrangement of the appa- ,out; said lining comprising a series of cylindrical sections of refractory material disposed end to end and closely fitting within said shell. each such section having an internal recess formed in each of its ends and supplementing the like recess in an abutting section; said tube comprising a series of cylindrical sections of porous refractory material disposed end to end within said lining, each ber.

DAVID G. BRANDT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,265,746 Chantraine May 14, 1918 1,545,155 Mehner July 7, 1925 2,311,350 Richardson Feb. 16, 1943 2,312,719 Kuhl Mar. 2, 1943 2,062,358 Frolich Dec. 1, 1936 

